Scientists have identified specially designed human antibodies that block key steps in alpha-gal syndrome (AGS), a potentially life-threatening red meat allergy caused by lone star tick bites. The findings were published in the Journal of Clinical Investigation.
Targeted Antibodies Block Alpha-Gal Mechanism
Researchers isolated 42 human antibodies by analyzing immune cells from people exposed to malaria. Laboratory experiments revealed that 13 of those antibodies bound to alpha-gal allergens.
The Tick-Borne Mechanism Behind the Allergy
Alpha-gal syndrome develops when a tick transfers alpha-gal sugar molecules from its saliva into a person’s bloodstream. This triggers an immune system threat response that can cause severe allergic reactions after eating red meat or consuming products containing alpha-gal, according to the Centers for Disease Control and Prevention. The lone star tick is most commonly associated with AGS in the United States.
Isolating Effective IgE-Binding Proteins
In blood-based experiments on isolated immune cells, investigators tested the 42 selected human antibodies to see how they interacted with alpha-gal allergens. While most of the antibodies did not perform well against the allergens, 13 successfully bound to them, according to the study.
Further analysis revealed that two specific antibodies, designated AG028 and AG050, could bind to Immunoglobulin E (IgE). IgE antibodies normally help the body fight parasites. However, they can also trigger allergic reactions when exposed to specific triggers like alpha-gal.
AG028 Suppresses Basophil Activation in Serum
The research demonstrated that antibodies AG028 and AG050 could block IgE from binding to key allergens in patient samples. Among them, the antibody AG028 showed the strongest potential in laboratory testing.
According to the study findings, AG028 reduced basophil activation—a rare type of white blood cell involved in allergic reactions—by as much as 86% in one patient’s serum. Although the experimental treatment did not entirely prevent allergic reactions and requires extensive further testing, the results indicate that targeted antibody therapies could eventually be developed to address the condition.
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